A conventional disk drive includes a head stack assembly to read and write data to and from a magnetic rotating disk. Generally, the slider should be substantially level relative to the magnetic rotating disk. If a slider of the head stack assembly is tilted too much, the slider may not read and write data to and from the magnetic rotating disk correctly. Thus, prior to installation of the head stack assembly in the disk drive, the head stack assembly is tested or calibrated using a conventional tester to determine a pitch static attitude of the head stack assembly.
The conventional tester transmits and receives laser beams to determine the pitch static attitude of the head stack assembly. However, the head stack assembly often contains gaps, which may distort or cause errors during the determination of the pitch static attitude of the head stack assembly by the head stack assembly. Thus, the conventional tester may erroneously determine that the head stack assembly contains problems with its pitch static attitude resulting in unnecessary adjustments or replacement of the head stack assembly. In addition, the conventional tester may erroneously determine that the head stack assembly does not contain problems with its pitch static attitude resulting in future failures of the disk drive.